DATE: 28 March 2000
TO: Keith Mille, Environmental Specialist
Office of Beaches and Coastal Systems
FROM: Jennifer Wheaton, Research Administrator
Coral Reefs and Hardgrounds, Resource Health & Assessment
FWC FMRI
SUBJECT: Indian River County Beach Restoration
Phragmatopoma caudata Mrch, 1863, the current correct name for the species, occurs in tropical high-energy coastal areas. In Florida, if occurs only on the east coast south from Cape Canaveral to just south of Key Biscayne, in the intertidal zone to depths of about 10 m. In central eastern Florida, Phragmatopoma lives principally on the exposed longitudinal ridges of coquinoid rock that occur from Brevard County south of Cape Canaveral to Jupiter Inlet in northern Palm Beach County. Reefs that occur on the southeast central coast of Florida are actually “coquinoid rock-sabellariid reefs”. The majority of this hardbottom habitat extends in an almost continuous band from just north of Sebastian Inlet in southern Brevard County south to Jupiter Inlet in Palm Beach County. In Indian River County, it extends for more than ½ mile offshore. Phragmatopoma typically occupies about 5% or less of the exposed coquinoid rock. However, Phragmatopoma colonies are the most conspicuous component of the attached biota. This is especially true in the high to middle intertidal zone, where colonies may cover most of the available hardbottom substrate because Phragmatopoma out-competes other reef types that have low tolerance to exposure at low tide. Other attached fauna (tunicates, sponges, and corals) and a diverse flora of attached filamentous algae occupy the remainder of the rock. The filamentous algae are probably the most important component. The hardbottom habitat is composed of all of these elements including the sandy areas between the ridges of the rock (Perkins et al 1997, & pers. comm).
The State of Florida and Florida Keys National Marine Sanctuary have recently (January 1998) prohibited collection of live sand within the Sanctuary stating that the resources exist due to the dynamic ecosystem of which sand and its associated meiofaunal communities are a major component. The Department of Environmental Protection denied permission for removal of “live sand” stating that the sand substrate is important habitat for grazers and detritivores and it contains an extensive and diverse macro-invertebrate community. Removal of live sand from the Sanctuary was determined to cause impacts to adversely affect marine productivity, fisheries, wildlife habitat and water quality. Thousands of species of infauna were identified in a study of soft bottom habitats off Hutchinson Island The sand borrow areas for the proposed Indian River County project impact an additional 522.3 acres of sovereign submerged lands when ecosystem function is considered.
Numerous invertebrates and fishes, including tropical fishes occupy the hardbottom habitat. Gilmore et al. (1981) stated that about 40 of these fishes are commercially or recreationally important. The coquinoid rock-sabellariid reef is also an important habitat for immature stages of the threatened green sea turtle (Ehrhart, 1992)
which feed on the diverse assemblage of benthic algae. Along with Phragmatopoma, a suite of animals are apparently restricted to the principal area of the habitat including the spiny lobster Panulirus laevicauda, the xanthid crab Menippe nodifrons (which lives in burrows within the Phragmatopoma colonies), the star shell Lithopoma tuber, and the croaker Bairdiella sanctaeluciae, a species of special concern (Gilmore, 1992). Gilmore stated that B. sanctaeluciae has only been found on the east coast in the principal area of the coquinoid rock-sabellariid reefs. In a letter to the National Marine Fisheries Service protesting certain proposed fishing regulations, David Hefflebower, President of Harbortown Marina stated “the fishing area from just South of Ft. Pierce to just North of Sebastian is the most productive area along the coast” (Appendix B, Final Comprehensive Amendment, 1998).
The accompanying SEAMAP figures (1, 2) show the distribution of nearshore hardbottom, off Indian River County. In 1998, the South Atlantic Fishery Management Council published its Final Habitat Plan for the South Atlantic Region which includes Indian River County, Florida. The plan defined essential fish habitat for the region and requirements for Fishery Management Plans specifically including the snapper/grouper fishery plan and the coral, coral reefs, and live/hard bottom habitat fishery management plan. The zoogeographic break between the temperate to tropical component of the Region occurs between Cape Canaveral and Jupiter Inlet. Indian River County lies within this transition zone. Off mainland southeast Florida the nearshore hardbottom habitats are the primary natural reef structures in this subregion. Use of hardbottom habitats was documented for newly settled stages of over 20 fish species. To date 192 fish species have been recorded in association with nearshore hardbottom habitats of mainland southeast Florida. In a 1997 study (Lindeman, 1997) nearshore hardbottom habitats had over 30 times the number of individuals per sample than natural sand habitats.
Hardbottom habitats are often centrally placed between mid-shelf reefs to the east and inlet habitats to the west. The Indian River Lagoon (primarily Aquatic Preserve) along with the offshore worm reefs and other hardbottom exemplifies this situation (Figure 3). The cross-shelf positioning, coupled with their role as the only natural structures in the area, indicates nearshore hardbottom may represent important Essential Fish Habitat resources.
Additional attention was sought for hardbottom essential fish habitat as habitat areas of particular concern (HAPC). Nearshore hardbottom habitats of southeast Florida ranked high in terms of ecological function, sensitivity, rarity, and probability of stressor induction. It was concluded that these rare habitats represent Essential Fish Habitat-Habitat Areas of Particular Concern for species managed under the Snapper/Grouper Fishery Management Plan and dozens of other species which co-occur with species in that management unit (SAFMC Habitat Plan, p. 107). The plants and animals that
live in these nearshore hardbottom habitats are highly adapted to the habitat which
is a high energy environment and which can not be replaced by proposed mitigation.
In the applicant’s videotape viewing guide, 5 bottom types were categorized and their distribution in sectors were described. Time available only allowed selected review of 16 (2hr) tapes originally forwarded. Sector 5 (tape 18,19) was not represented; tape 19 was forwarded 3/24 however the applicant was unable to locate tape 18. Hardbottom communities viewed in underwater video tapes of sectors 3 and 5 in particular fit the concept of essential fish habitat. Even the low relief segments have significant undercutting and overhangs and nooks and crannies offering tremendous spatial heterogeneity for the attached benthos (sponges, corals, algae) as well as the associated mobile fauna which included urchins, numerous species of tropical fish, fish important to anglers (snook, snappers etc) and even sharks.
Summary of Indian River County Beach Restoration Project
Sector / Fill (acres) / Hardbottom (acres) / Private / Private Fill / Public / Public Fill1 / 42.2 / 3.17 / 0% / 0 acres / 100% / 42.2 acres
2 / 36.1 / 8.04 / 92% / 33.2 acres / 8% / 2.8 acres
3 / 99.7 / 16.68 / 87% / 86.7 acres / 13% / 12.9 acres
5 / 102.8 / 12.91 / 75% / 77.1 acres / 25% / 25.7 acres
7 / 84.9 / 15.58 / 100% / 84.9 acres / 0% / 0 acres
All / 365.7 acres / 56.38 acres / 72% / 281.9 acre / 28% / 83.6 acres
According to the applicant information, proposed beach restoration activities will provide 281.9 acres of fill for 72% of shoreline in private ownership and only 83.6 acres of fill for 28% of shoreline in public ownership. The total proposed fill of 365.7 acres will result in covering 56.38 acres of hardbottom outright. However, the hardbottom habitat is actually comprised of the hardbottom and the interstitial sand. Total impacted habitat is therefore not enumerated by the applicant.
Although the applicant has categorized the hardbottom as types 2-5, it should be noted that although high relief hardbottoms provide shelter for adult species, the habitat
complexity of low relief hardbottoms is critical to newly settled and older juvenile life stages especially when they represent the only hardbottom habitat available. The
hardbottom represented by the worm reefs (Phragmatopoma caudata) provides
habitat for certain species which are unique to that habitat (Perkins, pers. comm.).
Although the scale is different in Figure 4 and Figure 5, the southern borrow area of 295.7 acres (Figure 4, application documents) definitely lies in the highly productive area of the South Atlantic Bight Oculina/hardbottom depicted in Figure 5 (Appendix C, Final Comprehensive Amendment, 1998). The central borrow site of 194.6 acres may also impinge into this area. Florida statutes protect reefs and corals. Corals are protected from harvest, sale, and environmental impacts that cause on-site mortality. The State of Florida has successfully prosecuted for damages to coral communities on the Florida east coast: grounding of the U.S. Navy nuclear submarine Memphis and the freighter Firat (Continental Shelf Associates, 2000), damages from ATT submarine fiber optic cable deployments off Dania, and beach renourisment dredging incidents off Sunny Isles (Blair et al. 1990) Dade County.
From a resource management perspective. loss of 56.38 acres of hardbottom and ancillary environmental perturbations for the proposed project is not in the public interest. Activities not in the public interest as stated in Section 373.414 (1) (a), FS:
Adversely affect the conservation of fish and wildlife ….diminish the current condition and relative value of functions being performed by areas affected by the proposed activity…..adversely affect the functions and relative value of the habitat within the area of the proposed project…..adversely affect the fishing or recreational values or marine productivity in the vicinity of the activity.
Mining sand, transporting, and depositing it on barrier island beaches has a history of resultant damages to marine benthic communities (Courtenay et al., 1974; Salvat, 1987; Kuehlmann, 1988; Blair et al., 1990). The dredges chronically stray resulting in physical damage including losses in structural rugosity, and taxonomic diversity (Brown et al., 1990; Rogers, 1990). Additionally, silt and sediments created by the dredging are detrimental to light quality and quantity at depth. Survival of corals exposed to elevated sedimentation implies that the most hardy of the species (Siderastrea radians and Stephanocenia michelinii ) tolerate 15 days of chronic sedimentation-burial (Rice and Hunter, 1992). Chronic sedimentation weakens community composition/structure (Clarke et al. 1993). Corals, in particular noted in sector 3 and sector 5, could tolerate short-term exposure to high turbidity; however, when the water is chronically turbid for extended periods of time, corals loose the ability to clear sediment because of energy losses. Teleniski and Goldberg (1995a; 1995b) demonstrated negative effects of sediment loads on hard corals at turbidity levels of about 18 NTU’S. The Florida administative threshold for temporary shut-downs of dredge operations is substantially higher at 29 NTU’s. Herrnkind et al (1988) showed increased siltation causes direct loss of critical habitat for spiny lobster recruitment.
In addition, sponges, algae, and other benthic dwelling sessile organisms become buried by the suspended sediments that are associated with the dredging. When sediment material is piped up on the beach there is a chronic runoff of silt-laden water. This further contributes to degrading the nearshore hardbottom habitats including corals, sponges, Phragmatopoma worm reefs, and mobile organisms.
The President of the United States issued an executive directive to form a Coral Reef Task Force. All federal agencies (including the United States Army Corps of Engineers) are required to participate and review programs and actions that impact on coral reefs. The Task force issued an Action Plan on 9 March that emphasizes conserving corals and reefs. Dredging is a major detriment to coral reef communities off southeast Florida and should be reviewed in the context of the Action plan: http://coralreef.gov/.
State Statutes require that activities on sovereignty lands shall be designed to minimize or eliminate adverse impacts on fish and wildlife habitat. The applicant states mitigative measures must be mutually agreed upon to compensate for the unavoidable environmental impacts of the proposed beach renourishment project. The transmittal memo states an artificial reef is proposed for hardbottom mitigation. It should be recognized by all parties that deployment of artificial structures in already productive areas carries a certain degree of risk and although sparse, the hardbottom may constitute valuable juvenile habitat and refugia that may be severely compromised by creating addtitional habitat conducive to predators (SAFMC Habitat Plan, p. 120). The cost of in-kind replacement for artificial substrate to replace even the amount of hardbottom proposed for direct burial would be prohibitive.
In Appendix C to the Draft Environmental Impact Statement, accompanying a December, 1995, Brevard County, Florida, Shore Protection Project Review Study: Feasibility Report, the U.S. Fish & Wildlife Service recommended that beach renourishment not take place in the area of the live worm reef-coquinoid reef habitat, and that other options should be explored. The Florida Game and Freshwater Fish Commission, in a letter to the U.S. Army Corps of Engineers concurred with the findings and recommendations of the USFWS.
LITERATURE CITED
Blair, S.M., B.S. Flynn, and S. Markley, 1990. Characteristics and assesment of Dredge related mechanical impact to hard bottom reef areas off northern Dade County, Florida. P.p. 5-14 in W. Jaap (editor), Proc. of the 10th American Academy of Underwater Sciences Diving for Science Symp., St. Petersburg.
Brown, B.E., M.D.A. LeTissier, T.P. Scoffin, and A.W. Tudhope 1990. Evaluation of the environmental impact of dredging on intertidal coral reefs at Ko Phuket, Tialand using ecological and physiological parameters. Mar.Ecol. Prog. Ser. 65(3): 273-281.
Clarke, K.R., R.M. Warwick, and B.E. Brown, 1993. An index of seriation related to disturbance in a coral reef assemblage. Mar. Ecol. Prog. Ser. 102 (1-2): 153-160.
Continental Shelf Associates, 2000. Survey II. Monitoring reattached hard corals at the Firat grounding site. Continental Shelf Associates, Inc. Jupiter, Florida, 310 pp.
Courtenay, W.R., D.J. Herrema, M.J. Thompson, W.P. Azzinaro, and J. Montfrans, 1974. Ecological monitoring of beach erosion control projects, Broward County, Florida, and adjacent areas. U.S. Army corps of Engineers, Coastal Engineering Research Center, Fort Belvior, Va. Tech. Memo. 41. 88 pp.
Ehrhart, L. 1992. Turtles of the worm rock reefs. The Florida Naturalist, Summer 1992: 9-11.